A national report on the state of breast cancer treatment and prevention has concluded that too little attention is being paid to the environmental triggers that lead to breast cancer, whose incidence continues to rise.

Studies show that environmental factors greatly influence breast cancer rates, and yet these have not been a high priority for those in the field, which has focused on diagnosis and treatment. But because environmental triggers can often be controlled, they represent a “tremendous opportunity” to prevent the disease, the researchers said in the report, Breast Cancer and the Environment: Prioritizing Prevention.

The committee, which reviewed volumes of research and statistics, cited several proven environmental risk factors for breast cancer that deserve more attention:

” At the federal level, only a small number of efforts target breast cancer and the environment,” the researchers wrote. “… at most, 10 to 11 percent of breast cancer research projects funded by the National Institutes of Health (NIH) and the U.S. Department of Defense (DoD) focus on environmental health.”

Breast cancer prevention also is underfunded in research and public health programs, the reported noted.

Furthermore, known high risk factors — such as alcohol consumption, high breast density, radiation, reproductive factors and a high body mass index after menopause — have not been studied for interactions with physical and chemical exposures.

“We need to know how and when environmental exposures, singly and in mixtures, influence breast cancer risk and how this risk may vary at different exposure levels or doses,” the study’s authors wrote.

Even though there is a strong relationship between breast cancer risk and a family history of breast cancer, most people contracting the disease have no family history of it. This argues for more focus on the environmental causes of breast cancer, according to the committee, particularly those that can be modified, such as increasing physical activity and reducing weight.

The report called out BPA or Bisphenol A, a component of some plastics, as an example of one environmental factor needing more investigation.

BPA, when exposure occurs prenatally, could promote inflammation in breast tissue, a risk factor for cancer, the researchers wrote. Similarly, a high fat diet promotes inflammation and has been deemed a risk factor for breast cancer.

Physical activity was another environmental factor called out as deserving more attention, but for its protective effects.

“Sufficient evidence exists to conclude that physical activity reduces the risk of breast cancer by 20 to 40 percent,” the report’s authors wrote.

Diet also can be a positive influence, offering some protective effects against breast cancer. Consumption of phytoestrogens in plants, accompanied by lower fat intake, has been shown to reduce breast cancer risk. One large study found an 11 percent decrease in breast cancer risk for the “healthy” pattern of eating a diet high in fruits, vegetables and whole grains.

In addition, the consumption of genistein, a bioactive compound found in soy, has been shown to reduce breast cancer risk later in life for those who consumed genistein during childhood. Some studies, however, suggest that the timing of consumption is critical, having found a suspected increase risk in mice that were exposed neonatally.

But chasing your salad with an alcoholic drink may not be advisable. Numerous studies have shown that even moderate alcohol consumption raises breast cancer risks. The reasons are not well understood, but alcohol appears to change the metabolism of estrogen, the report noted.

The IBCERCC was established by order of Congress in 2008. The committee’s report Prioritizing Prevention was the result of two years of review by the committee chairs and several members, representing federal agencies such as the National Institutes on Environmental Health Science, the National Cancer Institute, the Centers for Disease Control.

Graphic explanation: Figure 7.1. Distribution of NIH IC spending on projects related to breast cancer by CSO categories (FY 2008-2010). One vertical bar is drawn for each of the ICs. Colors within each bar represent the different CSO categories. For each IC, the size of the color bar indicates the proportion of breast cancer projects in the corresponding CSO category, whereas the number within the color bar indicates the proportion of projects in that category. This figure shows ICs that funded 1 percent or more of the total NIH breast cancer research. Relative to other ICs, substantially more projects in every category were funded by NCI, but the largest number fell into the Biology category (814 projects). The largest number of NIEHS-funded projects fell into the Etiology category (74 projects). For NIGMS, NIDDK, and NCRR, the largest category was Biology (56, 41, and 40 projects, respectively). For NHLBI, the largest category was Prevention, but many of the 44 projects in this category was explained in part by the inclusion of the Women's Health Initiative (WHI), which examines cardiovascular disease, cancers of the breast and colon/rectum, and osteoporosis, the most common causes of death, disability, and impaired quality of life in postmenopausal women. Most NIBIB breast cancer projects (45) focused on Early Detection, Diagnosis, and Prognosis. The largest category for NHGRI was Etiology (11 projects), which was followed closely by Biology (8).